Automatic transmission



y 1951 J. H. COHEN 2,561,499

AUTOMATIC TRANSMISSION Filed Feb. 28, 1947 s Sheets-Sheet 1 INVENT R.

y 24, 1951 J. H. COHEN 2,561,499

AUTOMATIC TRANSMISSION Filed Feb. 28, 1947 3 Sheet s-Sheet 2! INVEN OJuly 24, 1951 J. H. COHEN AUTOMATIC TRANSMISSION 3 Sheets-Sheet 5 FiledFeb. 28, 1947 mom 6 H QQN 0 I .V vm \wn m #0. 0 00m m mm W l s 0m 0m Livw A mw 0v n S we. 0 m9 v9 09 mm H U o 9 8.

INVHVTOR. JOSEPH H. COHEN Patented July 24, 1951 UNITED STATES PATENTOFFICE AUTOMATIC TRANSMISSION Joseph H. Cohen, Detroit, Mich.

Application February 28, 1947, Serial No. 731,503

This invention relates to transmission and more particularly toautomatic hydraulic transmission.

Broadly the invention comprehends the provision of an automatictransmission comprising a hydraulic coupling and planetary gear setinterconnected in a manner effective to provide for all desired outputspeed and drive ratios smoothly and automatically.

An object of the invention is the provision of a hydraulic transmissionfor automotive vehicles that is simple and economical in construction.

Another object of the invention is the provision of a transmissionincorporating a hydraulic coupling comprising cooperative impeller andrunner members and having a planetary gear system operatively arrangedintermediate thereof.

Another object of the invention is the provision of a hydraulictransmission for automatic vehicles comprising a simple arrangement ofhydraulic coupling and planetary gear system effective to provide for anautomatic infinitely variable transmission of power.

A further object of the invention is the provision of a hydraulictransmission for automotive vehicles comprising a hydraulic coupling anda planetary gear system interconnected therewith and automaticallyresponsive controls for the coupling and planetary gear system providingfor the effective automatic operation of the transmission infinitelybetween a multiple reduction drive ratio and substantially direct or 1to 1 ratio.

A yet further object of the invention is the provision of an automaticinfinitely operable automotive transmission comprising a hydrauliccoupling and a planetary gear system associated therewith wherein therelative speed between the input and output speeds of the couplingdetermines the drive ratios of the output member of the transmission.

Other objects and advantages of the invention will appear from thefollowing description taken in connection with the drawings, forming apart of the specification; and in which:

Fig. 1 is a vertical cross sectional view taken through an automatichydraulic transmission;

Fig. 2 is a vertical cross sectional fragmentary view of a modificationof the transmission shown by Fig. 1; and

Fig. 3 is a vertical cross sectional fragmentary view of a furthermodification of the transmission shown by Fig. l; and

Fig. 4 is a vertical cross sectional view of the automatic hydraulictransmission of Fig. 1 in- 6 Claims. (Cl. 74-688) 2 cluding the addedembodiments of Figs. 2 and 3.

Although numerous transmission have been devised for automatic operationincorporating combined hydraulic coupling and gearing arrangements, nonehas utilized the arrangement of simple hydraulic coupling and simpleplanetary gearing system wherein the planetary gear system is'sointerconnected with the hydraulic coupling that the output of thetransmission is determined by the relative speeds of the gears of theplanetary gear system as controlled by the relative speed existingbetween the input and output members of the hydraulic coupling. Thisarrangement permits of an automatic infinitely variable delivery ofpower from the output member of the transmission between a predeterminedratio as established by the gear ratio of the planetary gear system andthe means of control thereof and substantially a direct drive or 1 to 1ratio depending on the efficiency of the hydraulic coupling.

Referring to Fig. 1 of the drawings for more specific details of theinvention, l0 represents generally an automatic transmission comprisinga stationary housing It, an engine output or drive shaft I4, anintermediate powered shaft ii of the transmission, and the transmissionoutput or drive shaft IT.

The engine output shaft it constitutes the input shaft of thetransmission and has fixedly secured thereon a combination flywheel andfluid coupling impeller member It. The member I 8 has secured upon acentral hub thereof a shaft 20 which is arranged concentric to shaft l4and extends axially therefrom including a reduced portion 22 and aportion 24 providing a sun gear 26 the purpose of which will hereinafterappear.

Juxtaposed the impeller l8 and arranged for association therewith is arunner member 28 that is secured upon a short sleeve 30 mounted forrotation on bearings 3| supported upon shaft 20. The runner 28 isshrouded by a housing 32 secured to member I8 and having sealingengagement upon sleeve 30.

The sleeve 30 has splined at one end thereof a gear cage member 33providing a ring gear 3! arranged internally thereof in radial alignmentwith the sun gear 26. The sun and ring gears have arranged in meshingengagement therebetween a plurality of planet pinions 36 forming inconjunction with said other gears a complete planetary gear system. Theplanet pinions are rotatably mounted upon a carrier member 38constituting the intermediate sleeve shaft i6 concentrically rotatableabout shaft 20. The shaft The intermediate shaft l6 constitutes theforward drive output shaft of the transmission and the forward drivethereof is transmitted to the output shaft ll of the transmission by amanual shift mechanism 56 adapted to shift a ring gear 58 having aninternal spline from full line position coupling shafts l6 and I1together or to dotted line position providing for the transmission-ofpower from ring gear 46 to gear 46 thence from gear 54 to gear 68,effective to rotate shaft I] independently of shaft l6. As shown by Fig.-1, the shaft I1 is journaled in the housing l2 upon bearing 60 and atits end adjacent shaft I6 is supported upon bearings 62 mounted upon thefree extremity of shaft 20.

The runner member 26 has arranged in the wall thereof near its centralhuba plurality of openings 54 and 66 respectively, the purpose of whichwill hereinafter appear.

In a normal operation with the transmission set for forward drivewherein the mechanism 66 is in full line position, upon the rotation ofshaft H the impeller l8 and shaft 20 are driven initially effectingrotation of sun gear 26. During the idling speed of operation of the sungear 26. the resistance to rotation of output shaft IT and shaft 16 aredetermined by the weight of the vehicle with which the transmission isto be associated and other drive components of the vehicle to be drivenfrom shaft I6 such as to resist rotation of the planet gears 36 aboutthe transmission axis while at the same time the planet pinions arerotated about their own axis resulting in rotating the ring gear 34 andrunner 26 reversely to gear 26. At this stage of operation the runnerplaces only a slight load on the impeller member inasmuch as the liquidis normally confined during static condition and low speed of the runnerin a central chamber 68 near the runner hub. Although a chamber 66 ishere provided as a receptacle for the operating liquid for low speeds ofrot tion of the impeller and runner as cooperative lements so as toreduce drag placed on the peller when it is desired to solely rotate theimpe er independent of the runner, it is. not essentially necessarydepending upon the allowable drag that may be permissibly placed uponthe impeller by the liquid inthe coupling at idling and low speeds ofoperation thereof. As the speed of the shaft i4 is increased over thatof idling speed, the speed ofv the impeller and sun gear are likewiseincreased thereby impartinga greater lineal speed to the planet pinions.-With the increased speed of operation of tlie'impeller amoreinoticeable drag occursbetween the impeller and runner effective toresist the'reverse rotation of the impeller resulting in providing forthe imparting of motion through :shaft is to-output shaft It by way ofthe planet pinions rotating in an orbit as driven from the relativerotation of gears 26 and 34; During this 'phase of operation the outputshaft will be rotating'a't a multiple speed reduction and increasedtor'iiue multiplication depending upon the relative ratio provided bythe planetary gear system and the predetermined degree of drag providedbetween the runner and impeller.

A further increase in speed of the shaft i4 and impeller l6 results indecreasing the slip between the impeller and runner for as the speed ofsaid coupling member is increased the liquid is delivered fromthechamber 66 to the operating zone of the runner thereby providing moreoperating liquid foithe coupling.

As the slip is decreased between the impeller and runner the relativespeed of rotation between the sun gear 26 and ring gear 34 decreasesresulting in driving the shaft l6 at a reduced ratio from the startingratio delivered to the output shaft I1. The ratio drive of the shaft l6to the shaft 26 will continue to decrease infinitely as the slip betweenthe impeller and runner decreases until such time when they shall beoperating at top efficiency as a fluid coupling substantially at 1 tol'thereby effecting a similar drive of shaft l6 to shaft 26 ascontrolled by the differential of speed between ring gear 34 and sungear 26. It is to be observed that the transmitted power is automaticand infinite between the limit as governed by the gear ratio design andslip factor provided between the impeller-and runner and a substantially1 to 1 drive dependent on the slip occurring at the maximum operatingspeed of the fluid coupling. The drive likewise responds reversely uponthe decrease in speed delivered by the shaft l4 as described aboveinreference to the increase in-speed of shaft l4 and the elementsassociated therewith. This com-- pletes a forward cycle of operation ofthetransmission. w

The reverse operation of the transmission is effected by the combinedbraking action of brake 42 and the shifting of gear 66 to dotted lineposition wherein a direct transmission of force is provided leading fromshaft l4 through gear cage 33, gear 46, and gears 46 and 64 to gear 66splined to output shaft l1.

Fig. 2 of the drawings illustrates a modification of the structure shownby Fig. I specifically with regards to the control of the transmissionqwherein a brake band I02 is arranged for en- 'gagementupon gear cagemember 33, acting as a brake drum for ring gear 34.

With the addition of the braking control to the transmission it ispossible to positively regulate the output of the transmission morecompletely. The brake 33-Il2 can be controlled for operation by either aspeed governor associated with the drive'shaft l4 or in response to thetorque demand of the vehicle with which the transmission is associated.I The brake 33i02 shall be operable for the tary gear system. By brakingthe gear cage 3'3- and the ring gear 34 associated therewith the planetpinions a and output shaft l6 will be driven at a speed in keeping withthe drive ratios oftheplanetary gear system of the sun gear 26 to thering gear 34 thereby effecting a maximum torque output of the shaft H.

The brake 33 -162 is inactive during idling speeds of shaft l4 so thatas predetermined in accordance with vehicle design, weight, wheel of thesun gear. impartsmotion to the planet pinfriction, gear friction. andthe like the rotation ions 86 which in turn through this rotationthereof transmit said motion to ring gear 34 and runner 28 for thereverse rotation thereof. During the predetermined idling speeds ofrotation of impeller I8 associated with shaft I4 the impeller throughthe medium of the hydraulic fluid carried by the associated impeller andrunner members is not sufficient to retard the reverse rotation ofrunner 28. The brake 38-I02 is also to be inactive when the speed ofshaft I4 attains a predetermined figure or the torque demand placed onshaft I6 is as predetermined, wherein it is released and the impellerthrough the medium of the hydraulic fluid is effective to rotate therunner and ring gear attached thereto to thereby infinitely change thetorque output or speed reduction of shaft I6 from the maximum amountduring the locked relation of the ring gear to the planet pinions andsun gear to the condition of maximum efficiency between the impeller andrunner wherein the output shaft I6 operates substantially in the ratioof 1 to 1 to the shaft I4.

Fig. 3 of the drawings is a further modification of both of structuresshown by Figs. 1 and 2 and differs therefrom merely in the provision ofa further control over that afforded by Fig. 2 in the form of a pump 202for controlling the supply of hydraulic fluid to the fluid coupling whenit is required, that is when it is desirous to positively drive therunner 28 from the impeller I8. The impeller I8 and runner 28 of Fig. 3differ from the structure of Figs. 1 and 2 in that the housing 32affixed to the impeller is provided with a plurality of openings 204,said openings allowing the hydraulic fluid of the coupling to draintherethrough during the idling speeds of the impeller and the omissionof the openings 64 and 66 from the runner inasmuch as they have nofunction in view of the provision of a hydraulic fluid supply pump.

The pump 202 as here shown is of the conventional radial type and isdriven by a shaft 205 from an output means of the engine and isconnected at the intake thereof with the fluid sump of the transmission.The output of the pump is connected by suitable conduit 208 andappropriate fittings through a passage in the hub of runner 28 with azone intermediate the impeller and runner such that when the fluid isrequired by the fluid coupling it will immediately be received in theworking zone of the coupling.

The pump 202 is adapted to be operable just prior to the release ofbrake 38I02 in accordance with either predetermined speed of the shaftI4 or torque demand of shaft I6 such that the fluid may begin to fill upthe vortex provided between the impeller and runner effective to providefor the transmission of power therebetween. With the release of thebrake and the simultaneous delivery of fluid to the coupling the runnerwill be driven from the impeller with slippage thus controlling theoutput speed of shaft I6 as determined by the relative speed betweenring gear 34 and sun gear 26. As the speed of the impeller increases andthe fluid is delivered to the coupling to. fill same the speeddifferential between the impeller and runner will decrease untilsubstantially a 1 to 1 drive is attained therebetween thus effecting asubstantially 1 to 1 output drive of the shaft I6 to shaft I4.

As disclosed by Figure 4 the brake band I02 is pivotally mounted byactuating levers I04 to the stationary housing, said lever having anannular ring I05 at its other end adapted to be actuated by speedresponsive governors I06 mounted for rotation with and pivotallymoveable upon housing 32, effective upon the attainment of apredetermined range of speed of housing 32 to control the braking ofring gear 3| after the attainment of the predetermined speed of thehousing effective to actuate brake 33I02 and inhibit rotation of ringgear 34 and for a predetermined range of speed thereafter the brakingapplication is maintained but beyond said range the ends I01 ofgovernors I06 will move over the curved ends of the annular ring I05resulting in a release of the brake for any speeds therebeyond. Theannular ring is of the interlocking split variety permitting of theexpansion and contraction thereof due to the ends I01 of the governorsbearing internally thereon to expand same or the spring tensionrelationship of levers I04 acting to contract same depending upon thecondition of operation taking place.

While this invention has been described in connection with certainspecific embodiments, the principle involved is susceptible of numerousother applications that will readily occur to persons skilled in theart. The invention, therefore, is limited only as indicated by the scopeof the appended claims.

What I claim is:

1. In an automatic transmission, an input shaft, a fluid couplingcomprising cooperative impeller and runner members, said impeller beingdriven by the input shaft, an intermediate shaft, an output shaft, aplanetary gear system comprising meshing sun, pinion and ring gearsgearing the impeller and runner together, the sun g: a" being affixed tothe impeller, the ring gear being affixed to the runner and theplanetary pinions coupling the sun and ring gears together being affixedto the intermediate shaft, means integral with the ring gear, jack shaftgearing coupled to said means integral with the ring gear, shiftablemeans for directly coupling the intermediate and output shafts in oneposition and for coupling the output shaft to the jack shaft gearing inanother position, means for retarding the rotation of the intermediateshaft to provide for reverse operation of the transmission when theshiftable means couples the jack shaft gearing to the output shaft andan automatically actuated brake for controlling rotation of the ringgear.

2. In an automatic transmission, an input shaft, a fluid couplingcomprising cooperative impeller and runner members, said impeller beingdriven by the input shaft, an intermediate shaft,

an output shaft, a planetary gear system comprising meshing sun, pinionand ring gears gearing the impeller and runner together, the sun gearthereof being aflixed to the impeller, the ring gear thereof beingaflixed to the runner and the planetary pinions coupling the sun andring gears together being aflixed to the intermediate shaft,means-integral with the ring gear, an automatically actuated brake forcontrolling rotation of the ring gear, jack shaft gearing coupled tosaid means integral with the ring gear, shiftable means for directlycoupling the intermediate and output shafts in one position and forcoupling the output shaft to the jack shaft gearing in another position,means for retarding the rotation of the intermediate shaft to providefor reverse operation of the transmission when the shiftable meanscouples the jack shaft gearing to the output shaft and a fluid supplypump for controlling the operation of the coupling.

3. In an automatic transmission, a fluid coupling comprising cooperativeimpeller and runner members, a planetary gear system comprisingcooperative ring gear, sun gear, and planet pinions coupling theimpeller and runner members together, an intermediate output shaftdirectly coupled to the planet pinions, an output shaft, means couplingthe intermediate and output shafts together for direct drivetherethrough, gearincluding means for coupling the ring gear to theoutput shaft by way of the flrst means, means for retarding rotation ofthe intermediate shaft for the reverse operation of the output shaft,and brake means operably engageable with the ring gear for controllingthe operation of the runner and ring gear.

4. In an automatic transmission, a power input shaft, a fluid couplingcomprising cooperative impeller and runner members, said impeller beingdriven by the input shaft, an intermediate power shaft, a power outputshaft, a planetary gear system comprising meshing sun, pinion and ringgears gearing the impeller and runner together, the sun gear thereofbeing'aflixed to the impeller, the ring gear thereof'being aflixed tothe runner and the planetary pinion gears thereof being affixed to theoutput shaft, means integral with the ring gear, brake means operablyactuated into engagement with the ring gear for controlling the rotationthereof, fluid drain means arranged at substantially the outer peripheryof the coupling, jack shaft gearing coupled to said means integral withthe ring gear, shiftable means for directly coupling the intermediateand output shafts in one position and for coupling the output shaft tothe jack shaft gearing in another position, means for retarding therotation of the intermediate shaft to provide for reverse operation ofthe transmission when the shiftable means couples the jack shaft gearingto the output shaft and controlled fluid pumping means for supplyingfluid to the coupling at substantially the inner periphery of thecoupling between the impeller and runner.

5. In an automatic transmission, a power input shaft, a'fluid couplingcomprising cooperative impeller and runner. members, said impeller beingdriven by the input shaft, an intermediate power shaft, a power outputshaft, a planetary gear system comprising meshing sun, pinion and ringgears gearing the impeller and runner together, the sun gear thereofbeing affixed to the impeller, the ring gear thereof being aihxed to therunner and the planetary pinion gears thereof being aflixed to theintermediate shaft, means integral with the ring gear, automaticallyactuated brake means for controlling the rotation of the ring gear,means providing for drainage 'of the fluid from the coupling, jack shaftgearing coupled to said means integral with the ring gear,

. Number Name 7 Date 1,203,265 Radcliffe Oct. 31,' 1916 1,900,118Lysholm Mar. 7, .1933 1,949,816 Smith-Clarke Mar. 6, 1934 2,069,360 vDuflield Feb. 2, 1937 2,196,660 Dodge Apr. 9, 1940 2,203,546 Pollard,June 4, 1940, 2,204,779 Swennes June 18, 194.0 2,290,319 Dodge July-21,1942 2,301,294 Kuhns et al. Nov. 10,1942 2,366,063 Seybold Dec. 26,1944Thompson Nov. 4, 1947 8 shiftable means for directly couplingthe-intermediate and output shafts in one position and for coupling theoutput'shaftto the Jack shaft gearing in another pofltion, means forretarding the rotation of the intermediate shaft to provide for reverseoperation of the transmission when the shiftable means couples the Jackshaft gearing to the output shaft and pumping means operable forsupplying fluid to the coupling shortly prior to the release of thebrake from controlling the rotation of the ring gear.

6. In an automatic transmission, a power input shaft, a fluid couplingcomprising cooperative impeller and runner members, said impeller beingdriven by the input shaft, an intermediate power shaft, 9. power outputshaft, a planetary gear system comprising meshing sun, pinion and ringgears gearing th impeller and runner together. the sun gear thereofbeing aflixed to the impeller, the ring gear thereof being aflixed tothe runner and the planetary pinion gears thereof being affixed to theintermediate shaft, means integral v with the ring gear automaticallyactuated brake means engageable with the means integral with the ringgear for controlling therotation ofthe ring gear, means providing fordrainage of the fluid from the coupling, Dumping means operable forsupplying fluid to the coupling shortly prior to the release of thebrake from controlling the rotation of the ring gear, jack shaft gearingcoupled to the means integral with the ring gear, shiftable means forcoupling the intermediate and output shafts together in one position-of

